1. Field of the Invention
The present invention relates to oil/gas well testing equipment and more particularly relates to a transportable, self-supporting, modular well testing apparatus for use in hostile environments.
2. General Background
The search for oil and gas has become increasingly critical due to demand as opposed to available supply. Increasingly, oil companies and their geologists are forced to look for oil in remote portions of the globe including hostile environments such as, for example, arctic and anarctic regions, Canada, and the northern slope of Alaska where temperatures can be sub-freezing for days on end. Working in temperatures of forty degrees below zero (-40.degree. F.) is a necessity at times. Even in such harsh environments, oil and gas well production must be monitored on a daily and often round-the-clock, 24-hour basis in order to monitor certain parameters which indicate well quality, and the quality of crude oil and natural gas flow coming from the well.
Typically, well testing involves the receiving of a stream of fluid from the well which fluid stream includes crude oil, natural gas, water, sand, and various other components as is known in the art. It is also known in the art to treat the crude oil stream with an oil separator which mechanically divides the crude oil stream into its various parts including the oil itself, water, natural gas and other such gases. In typical well testing, a separator is utilized to divide the crude oil stream into its various components so that each fluid component can be measured to determine various parameters such as flow rate, flow quantity, temperature, and various other such desired values. Various well testing components usually include vessels and/or flow components, surge tanks, heat exchangers (steam, diesel, etc.), pumps, laboratory equipment, piping, meters and the like.
In hostile environments, equipment and personnel are put under a serious strain which can often lead to nonfunctioning or poor functioning of equipment. In arctic well testing, parameter values are sometimes taken at undesirably long intervals and with crude instruments which must necessarily be tough enough to withstand temperatures which can reach many degrees below zero and can cause more delicate instruments to ice-up and freeze. This creates error sources that can prove costly in properly evaluating a new well.
In the prior art, well testing equipment used in harsh environments has been wrapped and insulated on a piecemeal basis for protection with the personnel individually operating such piecemeal equipment by moving through the ice and snow from vessel to vessel and from valve to valve in order to operate the well testing equipment in such harsh circumstances. Fluctuations in weather can interrupt normal operations. At times an unattended technician will not make the measurements as often as are required and frequently the values taken for such measurements are erroneous because of the severe environment in which they are taken. Sometimes the valves, guages, and meters do not function properly because they are caked with ice and snow.
In such a harsh environment the incentive is quite low for an operator on site to perform his job with accuracy and with precision over a long period of time such as, for example, on twelve to twenty-four man-hour shifts.
Well testing equipment typically utilizes a number of valves which are used to open and close various flow lines and vessel so that oil/gas can be transmitted between the various components of the system as desired in order to perform the various well testing operations. These valves can become caked with ice and snow making their operation impossible or difficult in many instances. Some of the valves utilized in oil and gas well testing are relief-type valves which must discharge pressures in excess of design pressures for the system. Malfunction of these valves can be critical being a source of hazard and possibly catastrophe.
Inspection of well testing equipment and of well testing personnel by oil company officials or persons with the United States Geological Service, and other various agencies charged with protection of the environment becomes another problem where such officials must be required to travel through snow and ice in sub-zero temperatures to visit various well testing sites to visually inspect the equipment, its connections, and its proper functioning. When this equipment is caked with ice and snow, its inspection becomes difficult and indeed the harsh environment prevents the inspector from staying on site for any large period of time even when he is wearing heavy arctic gear and protective clothing.
An additional problem in the utilization of well testing equipment in harsh remote areas such as the north slope of Alaska or in Arctic or the like is the problem of transportation of the equipment to the site and its subsequent assembly. Most areas near the well site are covered with ice and snow and thus, specialized vehicles must be utilized in order to move equipment on site and off site. Equipment must not only be transportable, but is usually subjected to harsh treatment in transit. Roads can be unpaved, full of potholes and patterned with irregular, repetitive, bumpy surfaces which set up excessive vibration that can tear apart equipment. Lifting is often by forklift where the entire equipment weight is placed on a few square inches of surface, creating high stresses. A further problem is the assembly of equipment at its final destination in a sub-freezing environment where personnel can generally work only at reduced capacity for short periods of time due to the severeness of the environment, the occurrence of white outs, and the like.
It is to these problems that the present invention is directed.
Several devices have been patented showing various modular equipment/housing units directed to solving various problems. None of these devices teach the combination of the present invention and its solution to well testing in a harsh environment such as in arctic regins of the globe.
U.S. Pat. No. 4,016,951 issued to Charles W. Dick, et al, is entitled "Air Transportable Seismic Exploration System for Use on Ice-Covered Waters." That patent discloses a system which comprises a housing which contains equipment such as an engine, a compressor, means for boring holes in the ice, and acoustic signal generating means that can be lowered into the water through the holes in the ice. The housing is sufficiently lightweight that is can be easily transported from one location to another by helicopter or other aircraft. The heat generated by the engine is sufficient to provide a comfortable working environment for personnel within the housing and helps preventing freezing of equipment located within the housing.
"Modular Housing Units" is the subject of U.S. Pat. No. 4,012,871 issued to T. Netto, et al.
A "Collapsible Prefabricated House" is the subject of U.S. Pat. No. 3,992,828 issued to T. Ohe.
A prefabricated room cell in the subject of U.S. Pat. No. 3,633,323 issued to K. Eriksson, et al.
A prefabricated utility system is the subject of U.S. Pat. No. 4,221,441 issued to William Bain.
A "Method of Constructing a Transportable Prefabricated Room Element" is the subject of U.S. Pat. No. 4,120,133 issued to Franklin Rogers, et al. The room element has a rigid frame or chassis consisting of a full panel, composed of prefabricated panel sections rigidly connected in an end-to-end assembly by structural means, and prefabricated vertical load-bearing structures, rigidly connected to the panel adjacent the ends thereof, for supporting superimposed parts (for example, the roof or ceiling, or a superimposed room element). At least one of the load-supporting structures may be integral with a panel section. The panel sections form the bases of the corresponding regions of the room element and at least one of them is incorporated in a three-dimensional prefabricated room element section, of unit form, which unit comprises such vertical load-bearing or non-load-bearing structures substantially all of the installations, required in that part of the completed room element. The unit may be a bathroom unit, a staircase unit, heating unit, elevator shaft unit, or kitchen unit.
A "Portable Building" mounted upon skids is the subject of U.S. Pat. No. 3,023,463 issued to F. E. Bigelow, Jr.
Another shelter which is the subject of a patent is U.S. Pat. No. 3,123,186 issued to C. A. Adkinson, Jr., et al, entitled "Wall Construction for Shelter."
3. General Discussion of the Present Invention
The present invention solves the prior art problems and shortcomings in a simple, straightforward yet effective manner by providing a modular well testing unit for use in hostile environments which comprises a plurality of modular sections, the sections upon assembly forming an enclosed structure for housing the components of the well testing unit. Each modular section is rugged, self-supporting, and transportable by several available means including by air transport, truck, or rail. The construction allows compactness allowing loading on aircraft where space and weight are limited. The sections are assembled together by bolting structural members, for example, and by providing detachable fluid conveying connections between the different modular units for the various piping provided. Insulation is placed on walls which will be exterior walls upon assembly. Insulation provided on each individual module thus forms upon assembly an internal controlled environment which is surrounded by a substantially continuous external insulated shell. Walls which will be external and part of the shell are insulated while internal walls are preferably open allowing access between the adjacent modular sections. A sheet metal skin covers those walls of the modular section which will upon assembly form part of the external shell. The skin is first exteriorly welded to the frame and that skin is covered with fireproof fiberglass insulation batts held in place by wire or like means. Internally, access is allowed between adjacent modular sections for movement personnel as is necessary for the well testing operation. Electric wiring for lighting, heaters, pumps, computers, metering equipment and the like is explosion proof to prevent explosion in case of gas leaks. Junction boxes are also provided at interface of adjacent modular units with explosion-proof, electrical unions forming connections. Thus, the entire apparatus upon assembly is entirely pre-wired and explosion proof. The enclosed insulated environment allows, if desired, interior warming with connection heating. An intake line allows a production stream from an oil/gas well to be tested to be transmitted to the interior portion of the shell. Outlets are provided for discharging oil and other separated fluids from the assembled enclosure. A plurality of well testing fluid handling vessels are disposed respectively in the modular sections. A manifold for forming fluid flow connections between the outlet, the inlet, and the various vessels is provided with the manifold including detachable connections between the different modular units.
The present invention thus provides a controlled environment for not only personnel but for the well testing equipment itself, the manifolding, the various valves and connections, and electrical and metering equipment.
The present invention further provides a controlled environment which allows the use of sophisticated well measuring and data processing equipment, computers and the like and protects such equipment from the external hostile environment.
It is thus an object of the present invention to provide a modular well testing unit for use in hostile environments which can withstand severe temperatures for long periods of time without excess maintenance, needing a minimum of personnel for its operation.
Another object of the present invention is to provide a modular well testing unit for use in hostile environments having various modular section components which are prefabricated, structurally self-supporting, and individually transportable even over rough terrain which creates severe, potentially damaging shock or vibration, and can be assembled on site with a minimum of effort.
It is another object of the present invention to provide a modular well testing unit for use in hostile environments in which complete manifolding allows a comprehensive fluid flow interface between all of the module sections of the well testing unit.
It is another object of the present invention to prove a modular well testing unit for hostile environments where manifolding, interconnecting piping and flow route selection by operators is in an internal controlled environment.
Another object of the present invention is to provide a modular well testing unit for hostile environments which allows internally, access between the various modular sections after the entire assembly has been completed.
Another object of the present invention is to provide a modular well testing apparatus which is hazard-free from explosions.